使用 Java 8，如何为列表中的 obj[4] 设置字符串常量<Object[]>当且仅当它具有空值？

Question

I am getting resultSet which has 6 columns. Now, I am assigning that to List of Object Array. Fact is Object[4] of each object in the list may or may not be null . If it is having null value, I have to set the same with "System", a String constant value. How to do that using Java 8 ? Please assist!

List<Object[]> loanEntries = loanDAO.getLoanMappingDetails(QueryConstants.LOAN_MAPPING);

Answer 1

I understand that loanEntries is the variable you are talking about.

List<Object[]> loanEntries = new ArrayList<>();
        loanEntries.add(new Object[]{"a","b","c","d",null,"f"});
        loanEntries.add(new Object[]{"aa","bb","cc","dd",null,"ff"});

        loanEntries.stream()
                .filter(objects -> objects[4] == null)
                .forEach(objects -> objects[4] = "System");

        loanEntries.stream()
                .forEach(objects -> {
                    for (Object object : objects) {
                        System.out.println(object);
                    }
                });

output

a
b
c
d
System
f
aa
bb
cc
dd
System
ff